Cable outside insulation stripper



March 18, 1952 E. l. AYERs ET AL 2,589,471

CABLE OUTSIDE INSULATION STRIPPER Filed Dec. 30, 1950 2 SHEETS-SHEET l March 18, 1952 E, l. AYERS ET Al.

CABLE OUTSIDE INSULATION STRIPPER 2 SHEETS--SHEET 2 Filed De'c. 30, 1950 Patented Mar. 18, l1952 CABLE OUTSIDE INSULATION STRIPPER Ernest I. Ayers and Harley M. Ayers,

Martinsville, Ind.

Application December 30, 1950, Serial No. 203,695

s claims. (c1. :4o- 91) 1 This invention relates to a tool for use in slitting the cover insulation on a cable of that type wherein there are at least two conductors, each insulated, one from the other, and the two conductors are surrounded by one or more shields or ground wires which serve as a third conductor,

vand which lie immediately below the outside insulation.

Such a cable is used in drop service wiresfrom the pole to the house in running a line from the Wires on a pole line or the like to the house for electric service, In view of the fact that there is immediately underlying the outside insulating cover. these series of wires` constituting the third conductor, it is an exceedingly diiiicult job to remove the outside insulating cover in order to secure access to these wires and also to the two separately insulated cables. Heretofore this has been done laboriously by the operator using a pocket knife and whittling away on the outside cover, usually to the detriment of the third wires, damaging them or at least reducing their diameter by cutting into them.

It is very necessary that these encircling wires be not damaged to the extent of their diameters being reduced, otherwise the current carrying capacity is lowered.

Therefore it is a primary object of the invention to provide a tool which is to slit the outside insulation down to these encircling wires, without in the least damaging them, and yet which will permit the operator to roll back the slit insulation without any difficulty whatsoever.

It is a further primary object of the invention not only to slit the insulation as indicated, but to do so in one pulling operation so that the time required 'for that operation is reduced to a minimum.

These and many other objects and advantages of the invention such as the extreme simplicity and relatively low cost of manufacture, of the device, will become apparent to those versed in the art in the following description of one particular form of a device as'illustrated in the accompanying drawings, wherein Fig. 1 is a view in side elevation and partial section of a structure embodying the invention;

Fig. 2 is a view of the same structure in side elevation showing the device in an open position ready to receive a cable;

Fig. 3 is a view in transverse section on the line 3-3 in Fig. 1;

Fig. 4 is a view in top plan with a section of cable in place and partially slitted;

Fig. 5 is a view of the cable afterthe outside;

insulation has been slitted in top plan showing the interior construction; and

Fig. 6 is a viewin section through the cable on the line 6 6 in Fig. 5.

A body IU is formed to have a generally U-shaped cross section open from its underside. A pin or stud II extends transversely from one side of the body I0, herein shown as from the left-hand side. This pin II is screw-threadedly passed through both legs I2 and I3 of the body I0 at the forward end portion thereof, and is iixed in position by means ofl a nut I4 on the outer end of the stud II where it emerges from the leg I3.

On this pin II there is provided a shoulder I5 spaced outwardly from the leg "I2, so as to form an abutment for a roller I6 which is revolubly carried on the reduced diameter portion II extending outwardly from the shoulder I5, of the pin II. Any suitable means, herein shown as a hairpin I8 engaging in a groove ISI around the portion II outside of the roller I6 serves to retain the roller I6 in position on the pin II.

A very important characteristic of the roller I6 is that it have a circular blade section I9 to have an outer peripheral portion 20 which is not sharpened as has been the case heretofore in handling insulation, but is rounded to present a dull edge. We have one particular structure which is very suitable for the purpose wherein the thickness of the blade portion I6 is 3/64l of an inch, and the radius forming the edge 20 is half that thickness. The plane of the plate I6 is spaced outwardly from the leg I2 of the body IQ a distance atleast greater than one-half of the major width of the cable 2|.

Just back of the pin II, there is a pin 22 extending between and iixed to the two legs .I2 and I3, and on which is rockably mounted a toggle head 23. This head 23 extends downwardly be@ low the under edges of the body sides I2 and I3 to extend a distance suiiiciently therebelow to permit mounting on the left-hand face of the head 23 a roller 24.

A stub 25 is fixed to the head 23 to extend from the left-hand side thereof as an axle on which the roller 24 may revolve. In the form herein shown, the stub 25 is screw-threadedly engaged with the head 23 to extend rigidly therefrom.' The roller 24 is maintained longitudinally on the stub 25 by any suitable means, herein shown as by means -of the hairpin 26 engaging in a groove 21 around the outer end .portionof the stub 25 outside of the end of the roller V2II.

i The longitudinal, external contour of theroller 24 is very important in the present invention. This shape is best shown in Fig. 3, wherein the roller 24 is provided with outer end anges 28 and 29 with the periphery ofthe roller 24 reduced in diameter therebetween. Midway between the inner and outer iianges 28 and 29, the roller 24 is-increased in diameter to provide the outwardly rounding portion 30 to leave reduced diameter portions 3| and 32 on either side thereof adjacent the flanges 28 and 29. In other words, the roller 24 has an enlarged waist line as compared to the portions on either side of the waist which is designated bythe numeral 39.-

`The inner iange 28 clears the under edge of the leg I2 of the body I0. Y Y

An operating lever 33 is provided Witha U.- shaped cross section to have its frontend portion `straddle the lower and rear portion of the Vhead 23 and be pivotally connected thereto by means of the pin 34. The lever 33 continues rearwardly `therefrom to'have aV linger gripping end portion 35. This lever 33 is; positioned by means o'fits pivot attachment to the head v23 to be in paral- `lelism with the body Illthereabove.

' A bar link 36 has a forward end portion inserted within the lever 33 and is pivotly connected thereto by means of the pin 31 at a distance behind the Yhead 23 andthe pin 34. This bar 36 extends .upwardly and rearwardly to enter between the legs I2 and I3 of the body Il),` and have an endv 38 come into abutment with the forwardend 39 of an adjusting screwllil.

vr`'Ihis Yscrew 40 screw-threads throughv a rear portion'of the body II) and is xed in the 'desired adjustment by means of the lock nut 4 I. The-barV 36 has a finger A42 Vwhich ts over the top side of the screw end 39 so that the bar willrnot normally drop downwardly between the body legs I2 and I3 at that contact. The end 38 of the bar Y36 is compressively maintained in contact with lthe screw end 39 by meansof a tension spring 43 whichhas its forward end fixed to the head 23 and its rear end fixed to the upper portion of the body I6, the spring 43 extending upwardly between the legs I2 and I3 to be substantially confined therebetween. To limit the upper movement of the operating lever 33, so as to x a vdistance between the edge 29 of the roller I6 and the waist 3U of the under roller 24, an abutment 44 is provided on the underside of the lever 36 to extend downwardly therefrom to come 'intocontact with the web 45 of the lever 33, Fig.

`travel of the lever 33, the abutment'liilon the bar 36l also will come into contact with the web 45 of the lever 33 and thus stop further movement of the lever 33 toward the body I. Pulling downwardly on the lever 33, will bring the various shiftablevmembers into v*the relative positions as indicated in Fig. 2 where the roller 24 is spaced its maximum possible distance from the upper roller I6.Y Y y Y This spacing between the two Yrollersliuand 24 inthe wide open positions as" indicated"` in Fig. 2, permits `the cable'2 toy beplacedfth'ere'e between,V whereupon the lever 33 ri's'pulled up# wardly toward the body I3 to compressthecable 2l lbetween the two rollers. vThe `cable 2I'lis initially positioned centrally on the roller 24 with its relatively iiat side thereagainst', tovbe centered `on the waist 30.v The lever'33 is continued to -be pulledv toward the body |il, whi`-c h causes the edge '20,of 'the roller VI6 td'bitefinto the louter `insulation 48 of the cable2l.y `rIncidentally this insulation 48 may be either of rubber as indi'- cated in Fig. 3, or it may be of a fabric impregnated with some asphaltic or rubberized filler as indicated in Figs. 4-6. In either event, the operation for stripping the insulation remains the same. With the proper setting of the screw 46, the edge 20 is forced into the insulating cover 48 that distance which will cause the edge 20 to pass entirely therethrough, and compress the inner series of wires 49 which extend around the Vinner pair 56 of conductors down into a V-like formation as indicated in Fig. 3, there being suicient resiliency or space to permit that formation of the wires'49, all without in any way whatsoever cutting into those wires or reducing their diameters in any respect whatsoever. The cable 2 I is held in a fixed manner and the tool set as just described is pulled therealong, to form the slit 5I as indicated in Figs. 4 and 5. The edge 26 as it penetrates the outer insulation 48 maintainsthe cable 2| centrally over the waistjso that Vthe cableis in effect` spread downwardly therearound longitudinally of the roller 24 as the cable 2l passes relatively longitudinally thereacross. This means `that the upper portion of the cable 2I is placed under considerable tension so that when the edge '20 is brought compressively thereagainst, that rolling operation of the roller I6 causes the edge 26 to penetrate vvery readily through the cable insulation thus tensioned. Not only is that true, but the groove between the two cables of the pair 56 is centered in respect lto the edge 20 of the' roller I6 so that that edge'2 always comes therebetween, or rather to Yenter that groove wherein the wires 49 Ymay be `compressed to be out of the way' of the penetrating edge 2i).

Following the'relative travel of the Ytool along the cable 2i, the insulation 48 may be laid open as indicated in Fig. 5 so that it may be cut off transversely of the cable at the end ofthe cut portion, whereupon the wires 49 may be un- Wrapped and twisted into the conductor as is the usual practice. Therefore it is to-bev seen that by the combination of the roller 24 having the enlarged waist 36 and the roller I6 having the rel` atively thin blade I9 with a vrounded penetrating edge 29, the Cable to be operated upon is not only maintained in the proper position for the entrance of theedge 26 Ithrough-the outer insulation withoutv damaging the inter-shielding or `surrounding wires, but theentrance of the edge 2 0 is greatly facilitated by placing Vthe cable'initially under tension so as to cause the edges to tend to spring apart as `the relatively dull edge'2-6 is forced therethrough.l f This combinationof the two rollers inthe forms describedtogether with any suitable means Y'whereby the rollers maybe brought into a relatively fixed space apartspa-cing for the slitting operation constitutes the gist of the invention. v

Therefore, while we have herein shown and described the invention in the one particular embodiment, it is obvious that structural variations may be employed particularly in the means for carrying and' spacing apart the rollers, all without departing fromthej-spirit of the invention, Vand we therefore donotdesire to be limited totha'tprecise embodiment-beyond the limitations vwhich may 'be imposed-'by l`the following claims. Weclairnr* H LA tool for slitting outside insulationffrom a cable Carrying within that insulationian vinner separately insulated fpairlof. conductors .Wrapped around by-a' third Vr neutral conductor; comprising a roller having a thin section with a rounded edge as the periphery of the section; a. second roller having a central outwardly curving, bulging waist portion; means for mounting the two rollers in relation one to the other whereby the plane of said section includes a diametrical plane centrally through said waist portion. l

2. A tool for slitting outside insulation from a cable carrying within that insulation an inner separately insulated pair of conductors wrapped around by a third or neutral conductor, comprising a roller having a thin section with a rounded edge as the periphery of the section; a second roller having a central outwardly curving, bulging waist portion; means for mounting the two rollers in relation one to the other whereby the plane of said section includes a diametrical plane centrally through said waist portion; the longitudinal curvature of said waist being such that pressure of said rst roller against a cable resting on said waist will cause said outside insulation to be forced inwardly of the cable between conductors of said pair to apply a tension of the insulation across the line of contact therewith by said first roller.

3. A tool for slitting outside insulation from a cable carrying'within that insulation an inner separately insulated pair of conductors wrapped around by a third or neutral conductor, comprising a roller having a thin section with a rounded edge as the periphery of the section; a second roller having a central outwardly curving, bulging waist portion; means for mounting the two rollers in relation one to the other whereby the plane of said section includes a diametrical plane centrally through said waist portion; means for bringing said two rollers relatively one toward the other to limit the penetration of the cable by said rst roller edge through said outside insulation and press said third conductor to a limit determined yby bending between said pair of conductors.

4. A device for slitting insulation of a cable of at least two conductors comprising means over which the cable may be pressed laterally to carry side;

a. portionof the insulation on one side inwardly between said conductors to tension the opposite side; a rounded edged slitting roller in line centrally of said opposite side; and means forcing said slitting roller through said tensioned insulation.

5. A device for slitting insulation of a -cable of at least two conductors comprising means over which the cable may be pressed laterally to carry a portion of the insulation on one side inwardly between said conductors to tension the opposite side; a rounded edged slitting roller in line centrally of said opposite side; and means forcing said slitting roller through said tensioned insulation; said rst means embodying a surface having a relatively upwardly rounded portion limited to contact said cable insulation over that area lying between said conductors.

6. A device for slitting insulation of a cable of at least two conductors comprising means over which the cable may be pressed laterally to carry a portion of the insulation on one side inwardly between said conductors to tension the opposite a rounded edged slitting roller in line centrally of said opposite side; and means forcing said slitting roller through said tensioned insulation; said :first means embodying a surface having a relatively upwardly rounded portion limited to contact said cable insulation over that area lying between said conductors; and means limiting the travel of said forcing means to a predetermined degree of roller travel into said insulation.

ERNEST I. AYERS. HARLEY M. AYERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 554,982 Claflin Feb, 18, 1896 2,502,245 Charles Mar. 28, 1950 2,561,099 Costelow July 17, 1951 

